Telegraph system



1366- 1933- M. H. WCODWARD TELEGRAPH SYS TEM 2 Sheets-Sheet 1 Filed Jan. 26, 1932 FIG. 4

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INVENTOR MARION H. WOODWARD ATTOREEY Dec. 26, WOODWARD 1,940,896

TELEGRAPH SYSTEM- Filed Jan. 28, 1952 2 Sheets-Sheet 2 FIG. 2

lNVENTOR MARION H. WOODWARD ATTOR EY Patented Dec. 26, 1933 This invention relates to telegraph code systemsa d a sm t appa a u adap ed t be op rated byn'p rn o at d tape and m re p fi a lyt ap a atu with wh h tap sp e iou pr par d r t a smitters adapt d nd si nal hav n lus; us a zer p rt ns. ma al o be u d. t transm tnn -versa -.,do1 b1. cur en nals, and; conve selat a p ratu w t whic apes. pr v usly p a d ran mi er adap ed to s nd g al hav n p usi ndrminu porti ns. m y als e "us to t ansm t [si na of p us; .m nus andazeroportions- It th ef r an-o ie t of 'my mventi n t provid m ans fo im nat t e ze oport OI the three-portioncode; i g

It is a further objectto'insert' the .zero portion in. converse cases. v

.It is a still further; objectto render tapes punched in Wheat stone code and Morse cable code to be usedmterchangeably in transmitting messages over cable land lines, respectively.

Other objects or my invention will be obvious l and will presentthemselves hereafter to those familiar with the artupon reading the following description and referring tothe accompanying drawings, inwhichz H Fig; 1a represents a tape perforated iiQr transmitting Morse cable code and, below, the corresponding polarity ,as applied the transmitting line;

- i Fig. 1b represents ;a tape perforated for transmitting Wheatstonecode and; below, the corresponding polarity .as applied to the line; Fig. v2 shows, schematically, 'apparatus ior the transmission of Wheatstone signals from cable codetape;. Fig.3 shows-schematically, apparatus for the transmission of cable signals ;from -Wheatstone tape; and i f Fig. 4 shows in some detail a step-by-step transmitter and, in addition; a means foricausing the transmitter to step two center tape perforae tions at a time instead ofyonewhen such double" stepping is necessary. 1 i Y 1 The Morse cable code is a three-element code employing for its use positive, negative andjzero current portions to the line. The dots-are rem resented by positive current portions to the line, the dashes arerepresented -by-nega tive current portions to the line, and the space intervals are represented by zero current portions to the line.

which is actuated by apreviously prepared, tape, as shown in Fig. 1a,; Qn this tape the dotis represented by one perforation; above the center -o nter hol and alone. to the. cable at. g both Wheat-ston .ao Mors sable co esare si nalstransmitteo" rom t ie e equaiemments; it urtlie as omedtha t 5 code are not all Sign9i1 ;Qf'x u.ae en th; the first and third signalsbeingcf .equal length,

1 equal int ryal of tim o ':t ,ansmis iQn name y two ioorz ndz o elements resneet re r; an i i also-assumed th t cable code is equivalent to anelement .ot the the Wheatstonesign'al for a dot rjeguires two ele- -.ments' for .trapsmission that fora space requires These signals arensually sent by a transmitter ir fthevo s i r or seoiei b a. .sins e s foration below the center line, andthe space is r nresented'b thesbse o o either a do 1a dash-per oration thi ape a h p fi l lfifi isms-re en ed b oneeen e ho e alone th ees soth t th:19 .A W 11 consi t o s 41 1 da h. pa ,oorobioa on..vo b ie e en es 92 tape by: av erto ation abo a e te hole,

a eri ratlo b w an immedia el oll wll ciat d'w th lasfioenter o e- The. et Af.

:thereiore. wi oor esp le th to three 99nseou ive center :19

. has he pe fo at d en In the Wheats ne code, positive current 1 transm tted to thel n .io h d lls and d shes, i l and m d shes oreoistineii hed irom he slo :by thei .1ens h,.-a .slas i be n three. t mes t len t o a101E-=;.Th?=$bfl$ ar fr n entei 'P 5a neg ive ou en l menttbein S im l9 PM line-:The tanewh c i t on ete tll 2.5 Wheatsmne ansm tter're resent oo h perioration d re tl abore e ent -h le ands per o a io .di-reetl be ow the sam c nte bo a a sh wn-in F 1b slash is repr se te bye-atper orati abor a c ter hole and. so

foration eloelow .e oenterhole imm diately 9 l w na .ll e i rep es nt d h pe center hol Th rtao to -therewith. e A 1 e show i Figs. l-a -aand 'ljb. Jfmnrth si na s tha a transmitted, it is eridem ha in e sab e signal one i terva o time i r quir d-for. tra .mittingza .d Jd sh; r, pac lo th lowin 1 analysis, it is: assum tha hedoiws as i an space-signals ofthe Mo e cab e l os a e a "sig-nalso eoua len t andt ie eaoh s gna requires an interval of time consisting.,of two dot, dashuand spa e gslena s of: the l z e ts oo as onl and," :furthermore, that. these signals requine'pntwonelements, 'andthat for ,a dash requires .fopr elements. Thus, a Wheatstonedotcan betranspositive Morse .cablecode dot signal into 110 no add tional renova ion sssetwo elements, each occurring for half the time interval required for the transmission of the cable code dot, the first of these elements being positive and the second being negative. A Wheatstone space can be transmitted from a cable code space by converting the single Morse cable code zero signal into two elements both of which are of negative polarity. However, it is more difficult to transmit a Wheatstone dash from a cable code dash, as the Wheatstone dash is four elements long compared to a length of two elements for the Morse cable code dash. Therefore, a Wheatstone dash is twice as long as a cable code dash. But, a Wheatstone dash may be further broken up into two equal intervals of time, one time interval corresponding to two elements of positive polarity, the other time interval corresponding to one element of positive polarity and one element of negativepolarity. Thus, a Wheatstone dash, on the basis of the above analysis, is made upof two positive elements plus a Wheatstone dot.

- From this analysis it follows that a Wheatstone dot and a Wheatstone space may be transmitted from cable code tape without much difficulty, but, whenever a Wheatstone dash is to be transmitted from cable code tape, it is necessary'to stop the tape for a time interval equal to two elements and to supply locally a Wheatstone dot termination during this interval, the dash perforation in the cable code tape transmitting the first two elements of the Wheatstonedash signal anda locally supplied dot termination adding the final positive and negative elements.

A continuously rotating transmitter cannot readily be used for the above purpose, as the tape must be halted'for atime interval of two elements whenever a Wheatstone dash is to be transmitted from a Morse cable code tape. A step-by-step transmitter, operated in the same manner as those used on multiplex circuits, can, however, be used for this purpose. Such a transmitter is shown diagrammatically in Fig. 4. An apparatus for the transmission of Wheatstone signals from cable code tape is schematically shown in Fig. 2. A distributor of the standard type, consisting of a pair of transmitter rings 1 and 2 and a pair of operating rings3 and 4 over which brushes are revolved synchronously by means of a phonic motor (not shown), is used in connection with a step-by-step transmitter and a group of relays- The transmitter rings "consist of a solid ring '1 and a segmented ring 2 made up of operating segments 5 and 7 and. locking segments 66'. The operating rings consist of a solid ring 3 and a segmented ring :4 made up of receiving segm'ents 8' and 9, locking segments 10 and 11; and locking segments 12 and 13.

Whenever a Wheatstone dot (one positive element followed by one negative element) is to be transmitted, the transmitter operating magnet '14 is operated inthe normal manner of operation for step-by-step transmitters by the completion of a circuit from positive battery through the transmitter solid ring 1, the brushes 15, an operating segment 7, the transmitting operating magnet 14 to negative battery. The

' tape (not shown in Fig. '2, 'but shown in Fig. 4)

is stepped forward one center hole; 'This operation may be more clearly understood by reference to Fig. 4. When the brush passes from the operating segment 7, the operating magnet circuit is broken and the tongues are pulled upward by a spring. The dot and dash relay tongues have the peckers 18 and 19, respectively, at their free ends so arranged that either the dot or dash tongue may.close its contact when the corresponding perforation appears in the cable code tape, that is, operating segment prior to 7 inserted a dot tape signal.

For instance, assume that a dot is to be transmitted. Then, only the dot pecker 18 enters a previously punched hole in the cable tape and the. dot tongue closes its marking contact. When the brush 20 on the operating rings 3, 4 next comes to a receiving segment, such as 8, a circuit is established from positive battery through the operating winding of the locking relay 21, solid operating ring 3, brushes 20, receiving segment 8, through the tongue and spacing contact of the dot local relay 22, and then from the dot tongue 16 and marking contact of the dot portion of transmitter relay 14 to negative battery. This circuit from the operating winding of the locking relay 21 moves the tongue of relay 21 to its marking contact and thus establishes the circuit from positive battery through the operating winding of the line relay 23, through the tongue of the locking relay 21, to negative battery, operating the line relay 23 to marking and causing a dot pulse one half element long to be transmitted'to the line. As the brush passes from the receiving segment 8 on to locking segment 10, a circuit is established from positive battery through the operating winding of the locking relay 21, the solid operating ring 3, brushes 20, the first looking circuit 10, through the spacing contact and tongue of the dash local relay 24, the tongue and marking contact of the'locking relay 21 to negative battery. As the brush passes from the first locking segment 10, the circuit through the operating winding of the locking relay 21 is broken and this relay returns to its spacing contact, thus breaking the circuit of the operating winding of line relay 23 the tongue of which also returns to its spacing contact and begins to send out the negative element of the Wheatstone dot signal.

In the circuit described above, the locking relay 21 and, therefore, the line relay 23 are operated to their marking contacts for one element out of the two assigned to the dot impulse, so that a positive pulse and a negative pulse, each equal in length to one element, are transmitted for each 'dot perforation of the cable code tape. The result is a translation of the cable code dot into a Wheatstone dot. Simultaneously, segment 7 steps the'tape, say, for a dash signal.

Whenever a space is to be transmitted, the transmitter is operated in the manner described above but, as there is no perforation in the tape for the space, neither the dot nor the dash contacts of'the tape transmitter are closed, and, therefore, locking relay 21 and line relay 23 are held to their spacing contacts by the biasing circuit so that a space is transmitted to the line.

When a dash pulse is to betransmitted, the transmitter operating magnet 34 is operated in the normal manner by segment 7 and then released. Then'the dash pecker 19 rises through a dash perforation in the cable code tape, and the dash tongue 17 of the transmitter relay 14 closes its contact. When the brushes 20 on the operating rings 3 and 4 reach the next receiving segment, say 9, acircuit is established frompositive l a: battery through the operating winding or; thelocking'relay 21, the operating solid ring 3-, the

brushesizll, receiving segment 9, the dash transmitter tongue 1 7' of relay 14, the operating wind ing 25-01? the dash local relay 24 to negative bat-' tery. The current in: this circuit operatesthe tongues of the locking'relay' 21 and the dash cal relay- 24 to their marking contacts. As the brushes 20'pass from the receiving segment 9 to locking segment 11;, a circuit isestablished'from" positive battery through theoperating winding of the locking relay 21, the solid operating ring transmitter rings l and 2'passes from the operating segment '5'to the locking segment 6, acircuit is establishedfrom positive battery through the solid transmitter ring 1, the brushes 15, the locking segment 6', the marking contact and t'ongueof the transmitter relay 28, the operating winding 29 of the auxiliary-locking relay 30, the

lockingwinding 31'of'the transmitter relay :28,

the'operating winding 33 of the dot local relay 22 the transmitter operating magnet winding 34 to negative battery. The current in this circuit moves the tohgueof the auxiliary locking relay 30 to its marking contact, moves the tongue of i the dot local relay 22 to its marking contact,

holds the transmitter relay 28 to its marking contact, andfholdsthe transmitter 14 mm operated position. As the locking segment 6' takes up the entire length between successive operating seginents 5 and 7 on the transmitter rings 1 and 2,

the transmitter 14 is held in'its operated position during this entire time so that two cable code tlmeinterval'sor four time elementselapse before the transmitter 14 is again released. Thus, while the cable code tape is being stepped by segment 7 to the next or, say, dash signal, the signal for a dot, as explained above, is simultaneously transniitted-over circuits completed by rings 3 and4; but, u pon" further rotation of the rings, when brush 20 makes its contact with segment 9, and while segment 6 is still covered by brush (magnet' 14 being,- therefore, de-energized when the dot is being transmitted) and dash pecker 19 being on its marking contact, a circuit is completed,

when brush makes itsjcontact with segment 9 1 and subsequently withwsegments 11 and 13, as

above explained, for transmitting two elements of th'e Whe'atstone dash. Although segment 5 simultaneously steps the tape forward one center notch, a locking circuit, previously established throughthemarking contacts of transmitter relay 28, is energized when brush 15 passes over segment 6', holding magnet coils 14 energized and, therefore, keeping the dotanddash peckers away from the tape and in inoperative positions until after segment 7 (assuming that the drawing Fig. 1 shows the rings completely) is passed over again and segment 6 is covered by the brush 15. v s

1 Thus the transmitter is halted orkept from transmitting'asfar as signalspunched 'on-the Merse cable code tape are concerned, for one cable code time interval or two time elements.

forall dash perforations in the cable code tape. This makes possible the -four time elements necessary tot'rans'mit a Wheat's'tone dash, e. g;, two elernen'ts while se'gmentss, 1 1 and 13 are passed over by brush 20am two elements while seg-.

ments 8; 10 and 12' are passed over by brush 20; While the first-two elements are being transmitted the last third of segment 6, segment 5, and the first two thirds'of. segment- 6" are passed over by brush 1'5-. 'Whilethe secend two elements are being transmitted the la'st third or Segment 6, segment 7,; and the first two thirds of segments are assed over by brush 15; Thus,

when segment 9 is again reached by brush-2Q, all the relays will be reauy ror tileewsreadas explained above. In short, as the brushes on the operating ringspass rrai'n egment '11- to segment 13-, a circuit is-established from positive battery through the operating winding of the locking relay 21 ring 3 the brllshZOps'egment 13, tongue and markingcontacts of the auxiliary locking relay through the tongue and marking contact of the locking'relay 21 to negative battery. The current" in this cireuit holds the tongue of" the locking reiayzi to its marking contact. As the circuit" thre'ugh se'gment 13' is not broken until the brushes are passed on to the next receiving segment, e; gr," 8, the locking relay 21 and,-therefore the line relay '23 are both held to their marking contacts for the full length"- of time between successive receiving segments, namely, for two time elements, so that two positive impulses, each equal in length to one elemenn'are transmitted to line. When the-brushes pass from-locking segment 13 on to the next receiving segment, e. g., 8, both the dot andda'sh transmitter tongues 16 and 1'7- are in their back position so that both their contacts are open. 'A circuit at this time, however, is established from positive battery through the operating winding of the locking relay 21, through the operating solid ring 3 the brushes 20, receiving segment 8," tongue, and marking contact ofthe dot local relay 22 to negative battery. From this point on until the next receiving segment isjrea'ched, e. g., 9, the circuits function in the same manner as de scribed for a dottransmitted froma dot perforation in the-tape, name1y, transmittinga positive' element and a negative element to the line, thereby making, inuall, three positive :el'exnents and'one negative element whichis' the conventional Wheatstone dash,

Now, as the brushes 15 on the transmitter'rings 1 and 2passi from thelocklng: segment, at'the' beginning of thesupplementing. Wheatstone' dot signal, on to an operating segment, the circuit through the operating winding 29 0f the auxiliary locking relay 30; the locking winding 31 of the transmitter relay 28; and the operating winding3-3 of the dot local relay; 22-isbroken sothat these relays return to their spacing'conits let

Ice

tion to be transmitted whu'e segments in and 12,- for example, complete the dash" signal.

2 Thus, whenever the. circuitsareoperated by a dash perforation inthe transmitter'tafie, the dash transmitter tongue starts the transmission to the line'of the two positive impulses, 'e'a'fch' equal in length to one "element, and also causes the circuits to be established for locking up the trans;-

mitter to subsequently sees it frdnrsteppingthe tape for an additional two element time period; thus causingit to pause for one cable code signal unit having two elementsso that the dot termination of two additional elements, one positive and the second negative, can be supplied subsequently after the transmission of the first two positiveimpulses which both together occupy a time interval of two elements, making four elements all together.

Instead of the transmitter operating magnet, a

cam maybe used somewhat similar to {that clearly shown in Patent No. 1,542,779 to W. C. Peterman, and indicated by numeral 22 of Fig. 1 of that patent. The afore-mentioned patent discloses a mechanical meanswhich may be adapted or modified foroperating the pecker pins 18 and 19. 7

Whenever it is desired to transmit cable code signals from Wheatstone tape, an inversion of the above method suggests itself. From the analysis given above it is apparent that dots and spaces which take up the same or equivalent time elements in both codes may be easily transmitted. The dashes,- however, which take up two center holes-in the Wheatstone tape and one center hole in the cable tape, require extra treatment. Thus, whenever a dash is to be transmitted in cable code signals from a Wheatstone tape, it is necessary to step the transmitter twice for each dash signal or to cause the transmitter is to step two teeth for each dash signal instead of the normal one tooth. Apparatus for performing this function is shown in Fig. 3.,

In order to use Wheatstone tape with the cable code transmitter, the contacts of the dot tongue'and dash tongue of the transmitter may be connected so that thedot pecker the tongue to put positive battery on receiving segments 8 and 9 when its associated pecker enters a hole in the lower part of the tape, while for a dash, the dash pecker alone enters a hole in the upper part of the Wheatstone tape (see Fig. 1).

Referring more particularly to Fig. 3, a commonly used apparatus is schematically shown for transmitting cable code signals from a cable code tape employinga step-by-step transmitter, but the circuit is modified to include an additional relay 50 which is operated only upon the transmission of dash signals when a Wheatstone tape is used to send cable signals. Corresponding parts of Figs. 2 and 3 are similarly numbered and, therefore, only the. changed or new elements will be specifically enumerated below.

In order to more clearly describe the o eration of the apparatus shown in Fig. 3, a typical signal will be transmitted. For instance, assume that a dot is to be transmitted; then the dot pecker 18 enters a hole in the lower part of the Wheatstone tape and the dot tongue 16 makes its marking contact, putting positive battery on segments 8 and 9 of operating ring 43. Although the dash pecker 19 enters the upper perforation in the Wheatstone tape, the closing of the dash marking contact bythe dash tongue 17 produces no immediate result, as its circuit is opened at the spacing contact of the dot tongue. Dot tongue 16 still remains on'its marking contact and brush 20 then passes over, say, receiving segment 8. Thus a circuit is closed through the operating windings of dot locking relay 5i, dash locking relay 52, auxiliaryitransmitter relay 50, dot transmitting relay 54, and dash transmitting relay 55 to negative battery. The relays are all biased mechanically or electrically to' spacing but,

upon completion of the above circuit, the tongues of dot locking relay 51 and dot transmitting relay 54 go to marking position, while relays 52, 50 and 55 are held to spacing position, thereby sending a positive impulse to the cable and simultaneously establishing a holding circuit for dot relay 54 from positive battery on marking contact and tongue of dot locking relay 51, brush 20, continuous ring 3, operating windings of relays 51,,52, 50, 54 and 55. This locking circuit maintains the dot transmitting relay on its marking contact for an interval of time equal in length to two positive impulses, each equal in length to one element of the Wheatstone code, thereby causing circuits to be established for locking the dot transmitting relay and causing it to transmit one positive cable code signal unit which has a time duration of two elements and, therefore, corresponds to a cable dot, on the basis of our analysis of the two codes. Operating segment prior to 44 positions a dot in the tape.

When a cable space is to be transmitted from a tape having a Wheatstone space, neither of the peckers is permitted to move upward through the tape, as there are no operating perforations for a space in a Wheatstone tape. As a result. all the relays are held on their spacing contacts by their biasing windings, and the cable is grounded for a time interval equal to one cable code signal unit or two elements of the Wheatstone code, thus producing an effect in the cable corresponding to a cable space unit.

Whenever a cable is to be transmitted over the cable from a Wheatstone tape having a Wheatstone dash perforated thereon, additional or aux-:iiiary transmitter relay 50 is enerin addi -on to other relays enumerated below. Thus on a dash signal, only the dash pecker 19 a perforation onthe upper side of the Wheatstone tape. 1 -is causes the tongue 17 to prepare a c? suit from negative battery, marking contact of thedash operating transmitter relay 1'1, tonguell oi the dash operating transmitter 9; contact and tongue 16 of dot itter relay 14 to oneof the receiving segments 8 or 9. Then the circuit is continued through brushes 20, solid ring :3, operating windings oi dot locking relay 51, dash locking relay auxiliary transmitter relay 50, dot transmittin relay 5i, dash transmitting relay 55, to pos ive battery. Since the current now ough these circuits in a reverse direction, the tongues of dash locking relay 52, auxiliary transmitter 50 and dash transmitter re- 55 are held to their marking contacts, while tongues of relays 51 and 54 are held to spac- This results in the sending of a negative establishing of a holding circuit for dash relay from positive battery on operating winding of relays 55, 54, 55, 51,.continuous ring 3, segment 5'7, tongue and marking contact of dash locking relay 52 to negative battery. This looking circuit maintains the dash transmitting relay cn its'marking contact for an interval of time equal in length to two negative impulses, each equal in length to one element of the Wheatstone code, thereby causing circuits to be established for locking the dot transmitting relay and causing it to transmit one negative cable code signal unit which has a time duration of two elements and, therefore, corresponds to a cable dot, on the basis of our analysis of the two codes.

The above follows, provided, of course, that segment 44 has previously stepped the Wheatf complete a circuit to energize coil 64 and cause 1 in the Wheatstone tape.

stone tape to a dash signal. This has been assumed to be the case here. Thus, after brush 15 passes segment 44 (segments 8 and 56, say, are then transmitting a dot), transmitter 14 is ready for segment 9 to subsequently condition circuits for transmitting a cable code dash.

Whenever the relay 50 is operated, e. g., on all dash signals, and now we are assuming that segment 9 and associated relays willrespond so.

as to transmit a dash, an intermediate auxiliary segment 45' on the transmitter operating ring 41 is connected in a parallel circuit with the normal operating segment 44, so that the transmitter 14 undergoes an additional stepping'operation in order to advance the Wheatstone tape past the second Wheatstone dot perforation and in position for the perforation of the next signal ately after this intermediate stepping by seg-.

ment 44', the transmitter 14 is again operated through segments 45" and before the next receiving. segment is in position, so-that the sec ond perforation of the dash signal is skipped and the transmitter is prepared for the next signal;

Another means for performing this same function is indicated in Fig. 4. In this case the additional relay, which operates only on' dash signals, removes a back stop from the pawl which controls the stepping of the perforated tape, so

that whenever this back stop is removed the pawl is allowed to step two teeth and, thus, the second perforation of the dash character is skipped.

Fig. 4 is particularly drawn to schematically, show an additional modification of apparatus which may be used to step the; Wheatstone tape two center holes whenever relay 50, described in connection with the above descriptionof Fig. 2,

is energized. With this apparatus the normal stop 60 islowered Whenever a dash signal is to, be transmitted, so that stop 61 then limits the motion of pawl 65 of armature 62.. This is;accomplished whenever relay 50 marks so as to the tape .to be moved two center holes instead of one. Obviously, the spring biasing tongue 16 must be adjusted so as to make the tongue almost immediately responsive to the energization of operating magnet 34' so as to avoid any tearing of the tape by pecker 18. The apparatus shown is schematic only and is illustrative of one type of step-by-step transmitter adapted to operate with the apparatus shown in Fig. 3'. Thus, a

Wheatst0ne tape is shown moving from right to left. Magnet 34' corresponds to magnet 34' of,

Fig. 3, 18 is the dot pecker andyl6 is the dot tongue, all of which correspond to apparatusindicated by similar numerals in Fig. 3.

It is to be noted in the above descriptions that Thus segment 44 will in Fig. 2 the dot pecker has been positioned so as to enter an upper or dot-perforation in the Morse cable code tape, while in Fig. 3 the dot pecker. has been positioned to enter a lower perforation of the two operative perforationsin the Wheatstone code tape. The perforations entered by the dash pecker in both these cases are obvious. Althoughspecific apparatus and methods for obtaining the translation of one code into another have been described above, I do not intend to be limited to the detailed or specific means of accomplishing this result herein disclosed, but only by the accompanying claims.

What is claimed is: l 1. In an automatic telegraph system, a transmitting station, a receiving station, a line connecting said stationsgatape perforated with a three-element code including zero as one of its elements, a transmitter at said first station controlled by said tape, and means at said first station to feed the tape through one perforation in a predetermined time interval when a dot is transmitted, and to feed the tape through one;

' perforation in twice the predetermined time interval when a dash is transmitted, to said re- 1 ceiving station.

2. In an automatic telegraph system, a transmitting station, a receiving station, a'line connecting said stations, a tape perforated with a two-elementcode having plus and minus elements, 'a' transmitter at said first station controlled by said tape, and means at said first station to feed the tape through one perforation in a predetermined time interval when a dot is transmitted, and to feed the tape through two perforations in an equivalent time interval when a dash is transmitted, to saidreceiving station.

3. In anautomatic telegraph system, a trans- "mitting station, a receiving station, a line connectingnsaid stations, a tape perforated with a 1 three-elementcode including zero as one of its elements, a transmitter at said first station controlled ,by said tape, stepping means for said tape, anda distributor having a set of segments, the odd segments of said set being adapted to 1 cause' said stepping means to feed the tape through oneperforation in a predetermined time interval when a dot is transmitted, the alternate segments of said set being adapted tocause said stepping means to feed the tape through one per- 1 foration in twice the predetermined time interval when adash istransmittedr e 4. In an automatic telegraph system, a transmitting station, a receiving station, a line connecting said stations, a tape perforated with a two-element code having plus and minus elements, a transmitter at said first station controlled by said tape, stepping means for said tape, and a distributorhaving a set of segments, the

alternate od d segments of said set being adapted 7 to cause said stepping means to feed the tape through one perforation in a predetermined time interval when a dot is transmitted, the intervening odd segments of said set being adapted to cause said stepping means to feed the tape through an additional perforation only when a dash is transmitted;

, MARION H. WOODWARD. 

